Project Summary Child maltreatment is highly prevalent and strongly associated with a range of adverse health outcomes in adults. Multiple human and non-human primate cohorts have collected prospective measures of exposure to child maltreatment and followed participants into adulthood collecting measures of physical and cognitive health. This conference would bring together the leaders of the major longitudinal human and non-human cohorts and experts in measurement and harmonization for a meeting on cross cohort harmonization focused on the relationship of early childhood maltreatment and adult physical and cognitive health. The aims and products of the conference would be: 1) Clear definition and conceptualization of childhood maltreatment that can be studied across cohorts and approaches for uniform recoding of already-collected data and harmonization of measures; 2) Identification of health outcomes and measures that can be used across cohorts as well as a plan for harmonizing measures already used; 3) Articulation of principles for cross species analyses; and 4) Dissemination of resources to provide guidance to investigators in cross cohort analysis of longitudinal data. These aims will advance the field of cross-cohort collaboration to allow attendees to answer key questions in the field about the causal link between early childhood exposure of child maltreatment and later physical and cognitive health outcomes. This work will directly impact the development of intervention efforts to ameliorate the impact of early life exposure to child maltreatment and poor health outcomes across the lifespan.